1. Field of the Invention
The present invention relates to an improvement in a catalytic body fixing structure for fixing a catalytic body to an exhaust pipe serving as part of an exhaust system joined to an engine, the catalytic body having a cylindrical case made of a material different from the exhaust pipe.
2. Description of Background Art
Heretofore, a structure where a catalytic body is housed in and fixed to an exhaust pipe has already been known from Japanese Patent Laid-open No. Sho 50-92855, for example. According to the known structure, the exhaust pipe and a case of the catalytic body are made of the same material. The catalytic body is housed in and fixed to the exhaust pipe by welding a bracket that is welded to an inner surface of the exhaust pipe to the case.
If the case of the catalytic body, the exhaust pipe, and the bracket are made of the same material, then the catalytic body can be fixed to the exhaust pipe by welding as is the case with the conventional structure. However, if the case of the catalytic body and the exhaust pipe are made of different materials, it is difficult to provide the above welded fixing structure. Therefore, there has been a limitation in the background art on the freedom in choosing materials for the case of the catalytic body and the exhaust pipe.